Molecular spectroscopy in the microwave to millimeter wave region can be used in constructing Microwave or millimeter-wave atomic clocks and other systems that require accurate timing signals. Atomic clocks excite the gas within a gas cell using mm-wave radiation induced by a RF transceiver and the system detects the rotational quantum transition of dipolar molecules for a reference. The gas cell is ideally a hermetically sealed environment including a desired target gas at a stable low pressure. Millimeter-wave chip-scale atomic clocks (mmWCSAC) can be used in a variety of product applications to provide a highly stable and accurate clock signal. Contemplated mmWCSAC designs integrate a chip-scale gas cell (e.g., physics cell) with an application specific integrated circuit (ASIC). However, difficulties arise in producing a low leakage chip-scale or wafer-scale gas cell that will maintain a desired cavity pressure over a product lifetime of several years or more. In particular, if the pressure and/or humidity within the mmWCSAC drifts too far from the originally manufactured specification through leakage, the cell will not function as intended due to pressure-broadening phenomena and/or improper attenuation at the dipolar molecular resonance.